INFINITI QX56 2007 Factory Service Manual

TROUBLE DIAGNOSIS FOR SYSTEM
TF-99
< SERVICE INFORMATION >
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CAN Communication LineINFOID:0000000003532551
DIAGNOSTIC PROCEDURE
1.CHECK CAN COMMUNICATION CIRCUIT
With CONSULT-II
1. Turn ignition switch “ON” and start engine.
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” within CONSULT-II.
3. Perform the self-diagnosis.
Is the
“CAN COMM CIRCUIT [U1000]” displayed?
YES >> Print CONSULT-II screen and go to LAN-40.
NO >> Inspection End.
ATP SwitchINFOID:0000000003532552
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK ATP SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
SDIA1850E
Monitored item [Unit] Content Condition Display value
ATP SWITCH [ON/OFF] Condition of ATP switch• Vehicle stopped
• Engine running
• A/T selector lever “N"
• Brake pedal depressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is
operating.) ON
Except the above OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
40 L ATP switch• Vehicle stopped
• Engine running
• A/T selector le-
ver “N"
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)0V
Except the above Battery voltage

TF-100
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
3. Read out the value of “ATP SWITCH”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND ATP SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the ATP switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 40 and ATP switch harness connector F55 ter-
minal 8.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Check continuity between ATP switch harness connector F55
terminal 9 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever
“N"
• Brake pedal de-
pressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.) ON
Except the above OFF
SDIA2391E
Connector Terminal ConditionVoltage
(Approx.)
E14340 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N"
• Brake pedal de-
pressed4WD shift switch: 4H
to 4LO or 4LO to 4H
(While actuator motor
is operating.)0V
Except the aboveBattery
voltage
SDIA2755E
Continuity should exist.
SDIA2756E
Continuity should exist.
SDIA2394E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-101
< SERVICE INFORMATION >
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4.CHECK ATP SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch. Refer to TF-22, "
Location of Electrical Parts".
4. Push and release ATP switch and check continuity between ATP
switch terminals 8 and 9.
OK or NG
OK >> GO TO 5.
NG >> Replace ATP switch. Refer to TF-22, "
Location of Elec-
trical Parts".
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 6.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
6.CHECK ATP WARNING LAMP
1. Turn ignition switch “ON”. (Do not start engine.)
2. Move A/T selector lever to "P" position.
3. Set 4WD shift switch from "4H" to "4LO" or "4LO" to "4H".
Does ATP warning lamp turn ON while switching?
YES >> GO TO TF-109, "ATP Warning Lamp Turns ON" .
NO >> Inspection End.
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 second.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch. Refer to TF-22, "
Location of Electrical Parts".
4. Push and release ATP switch and check continuity between ATP
switch terminals 8 and 9.
5. If NG, replace the ATP switch. Refer to TF-22, "
Location of Elec-
trical Parts".
Terminal Condition Continuity
8 - 9Push ATP switch Yes
Release ATP switch No
SDIA2757E
Terminal Condition Continuity
8 - 9Push ATP switch Yes
Release ATP switch No
SDIA2757E

TF-102
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
TROUBLE DIAGNOSIS FOR SYMPTOMS
4WD Shift Indicator Lamp and 4LO Indicator Lamp Do Not Turn ONINFOID:0000000003532553
SYMPTOM:
4WD shift indicator lamp and 4LO indicator lamp do not turn ON for approx. 1 second when turning
ignition switch to “ON”.
DIAGNOSTIC PROCEDURE
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector
terminals and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relay
box. Refer to PG-3
.
• 20A fuse No. 53 located in the IPDM E/R. Refer to PG-3
.
• Harness for short or open between battery and transfer control unit harness connector terminals
47.
• Harness for short or open between battery and transfer control unit harness connector terminal
29.
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1, and 3.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector terminal 30.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and
transfer control unit harness connector terminals 16 and 22.
• Battery and ignition switch. Refer to PG-3
.
• Transfer shut off relay. Refer to TF-51, "
Power Supply Circuit for Transfer Control Unit" .
2.CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
Connector Terminal Voltage (Approx.)
E14216 - Ground
0V 22 - Ground
E14329 - Ground
30 - Ground
Battery voltage
47 - Ground
WDIA0165E
Connector Terminal Voltage (Approx.)
E14216 - Ground
Battery voltage 22 - Ground
E14329 - Ground
30 - Ground 0V
47 - Ground Battery voltage
WDIA0166E

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-103
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3. Check continuity between transfer control unit harness connec-
tor E142 terminals 3, 6, E143 terminal 45 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3.CHECK COMBINATION METER POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check voltage between combination meter harness connector
terminal and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between combination meter harness connector
terminal and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair
or replace damaged parts.
• 10A fuse No. 14 located in the fuse block (J/B). Refer
to PG-3
.
• Harness for short or open between battery and combination meter harness connector M24 ter-
minal 24.
• Ignition switch. Refer to PG-3
.
4.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.Continuity should exist.
SDIA2691E
Connector Terminal Voltage (Approx.)
M24 24 - Ground 0V
WDIA0151E
Connector Terminal Voltage (Approx.)
M24 24 - Ground Battery voltage
WDIA0152E

TF-104
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 terminal 2 and
combination meter harness connector M24 terminal 32.
- Transfer control unit harness connector E142 terminal 11 and
combination meter harness connector M24 terminal 31.
- Transfer control unit harness connector E142 terminal 12 and
combination meter harness connector M24 terminal 33.
- Transfer control unit harness connector E142 terminal 21 and
combination meter harness connector M24 terminal 30.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Disconnect transfer control unit harness connector.
3. Turn ignition switch “ON”.
4. Ground the following terminals using suitable wiring.
- Transfer control unit harness connector E142 terminal 2 and
ground.
- Transfer control unit harness connector E142 terminal 11 and
ground.
- Transfer control unit harness connector E142 terminal 12 and
ground.
- Transfer control unit harness connector E142 terminal 21 and
ground.
Do indicator lamps turn on?
OK >> GO TO 6.
NG >> Replace combination meter. Refer to DI-21, "
Removal
and Installation of Combination Meter".
6.SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 7.
7.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> Inspection End.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
4WD Warning Lamp Does Not Turn ONINFOID:0000000003532554
SYMPTOM:
Continuity should exist.
WDIA0160E
SDIA2772E

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-105
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4WD warning lamp does not turn ON when turning ignition switch to “ON”.
DIAGNOSTIC PROCEDURE
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector
terminals and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relay
box. Refer to PG-3
.
• 20A fuse No. 53 located in the IPDM E/R. Refer to PG-3
.
• Harness for short or open between battery and transfer control unit harness connector terminals
47.
• Harness for short or open between battery and transfer control unit harness connector terminal
29.
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1, and 3.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector terminal 30.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and
transfer control unit harness connector terminals 16 and 22.
• Battery and ignition switch. Refer to PG-3
.
• Transfer shut off relay. Refer to TF-51, "
Power Supply Circuit for Transfer Control Unit".
2.CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
Connector Terminal Voltage (Approx.)
E14216 - Ground
0V 22 - Ground
E14329 - Ground
30 - Ground
Battery voltage
47 - Ground
WDIA0165E
Connector Terminal Voltage (Approx.)
E14216 - Ground
Battery voltage 22 - Ground
E14329 - Ground
30 - Ground 0V
47 - Ground Battery voltage
WDIA0166E

TF-106
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
3. Check continuity between transfer control unit harness connec-
tor E142 terminals 3, 6, E143 terminal 45 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3.CHECK COMBINATION METER POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check voltage between combination meter harness connector
terminal and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between combination meter harness connector
terminal and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair
or replace damaged parts.
• 10A fuse No. 14 located in the fuse block (J/B). Refer
to PG-3
.
• Harness for short or open between battery and combination meter harness connector M24 ter-
minal 24.
• Ignition switch. Refer to PG-3
.
4.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 terminal 5 and
combination meter harness connector M24 terminal 34.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.Continuity should exist.
SDIA2691E
Connector Terminal Voltage (Approx.)
M24 24 - Ground 0V
WDIA0151E
Connector Terminal Voltage (Approx.)
M24 24 - Ground Battery voltage
WDIA0152E
Continuity should exist.
WDIA0154E

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-107
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5.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Disconnect transfer control unit harness connector.
3. Turn ignition switch “ON”. (Do not start engine.)
4. Ground the following terminal using suitable wiring.
- Transfer control unit harness connector E142 terminal 5 and
ground.
Does 4WD warning lamp turn on?
OK >> GO TO 6.
NG >> Replace combination meter. Refer to DI-21, "
Removal
and Installation of Combination Meter".
6.SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 7.
7.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value" .
OK or NG
OK >> Inspection End.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
4WD Shift Indicator Lamp or 4LO Indicator Lamp Does Not ChangeINFOID:0000000003532555
SYMPTOM:
4WD shift indicator lamp or 4LO indicator lamp does not change when switching 4WD shift switch.
DIAGNOSTIC PROCEDURE
1.CONFIRM THE SYMPTOM
Confirm 4WD shift indicator lamp and 4LO indicator lamp turn on when ignition switch is turned to ON.
Do 4WD shift indicator lamp and 4LO indicator lamp turn on?
YES >> GO TO 2.
NO >> Go to "4WD Shift Indicator Lamp or 4LO Indicator Lamp Does Not Change".
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to TF-57, "
4WD Shift Switch".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK SYSTEM FOR WAIT DETECTION SWITCH
Perform trouble diagnosis for wait detection switch system. Refer to TF-60, "
Wait Detection Switch".
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK SYSTEM FOR NEUTRAL-4LO SWITCH
Perform trouble diagnosis for neutral-4LO switch system. Refer to TF-54, "
Neutral-4LO Switch".
SDIA2774E

TF-108
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to TF-99, "
ATP Switch" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6.CHECK SYSTEM FOR 2-4WD SOLENOID
Perform trouble diagnosis for 2-4WD solenoid system. Refer to TF-80, "
2-4WD Solenoid".
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7.CHECK SYSTEM FOR TRANSFER CONTROL DEVICE
Perform trouble diagnosis for transfer control device system. Refer to TF-72, "
Transfer Control Device".
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
8.CHECK SYSTEM FOR ACTUATOR MOTOR
Perform trouble diagnosis for actuator motor system. Refer to TF-64, "
Actuator Motor".
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
9.CHECK SYSTEM FOR ACTUATOR POSITION SWITCH
Perform trouble diagnosis for actuator position switch system. Refer to TF-69, "
Actuator Position Switch".
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
10.SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 11.
11 .CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 12.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
12.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to TF-128, "
Disassembly and Assembly".
2. Check transfer inner parts.
OK or NG
OK >> Inspection End.
NG >> Repair or replace damaged parts.